Trough solar energy collector systems use parabolic trough-shaped reflectors to focus the sun light energy onto a receiver pipe running at the focus of each of the parabolic trough reflectors. Because of their parabolic shape, the trough reflectors can focus the sun's light energy at 30-70 times or greater than its normal intensity on the receiver pipe. The concentrated energy heats a heat transfer fluid, usually oil, flowing through the receiver pipe. This heated heat transfer fluid is then used to generate steam which powers turbines that drive electric generators. The reflectors are generally aligned on a north-south axis and the trough is rotated to follow and track the sun to maximize the sun's energy input to the receiver pipe.
The efficiency of the trough solar energy collector system is maximized when the parabolic trough reflector and the receiver pipe are aligned properly. If the parabolic trough reflector and the receiver pipe are not properly aligned, some of the sunlight will not be focused on the receiver pipe and wasted. Thus, in order to operate a solar thermal field at its optimum efficiency, the trough reflector/receiver pipe alignment must be properly maintained. Currently available parabolic trough reflector and receiver pipe technologies, however, can not maintain their alignment permanently and their alignment must be manually checked and adjusted periodically. Because a typical solar thermal field may comprise hundreds or even thousands of parabolic trough reflectors, maintaining the proper alignment between the parabolic trough reflectors and the receiver pipes poses significant challenges and cost to the operation of a solar thermal field.